Multiple issues with Focus Merge

[DigitalStirling]

Hi guys

Focus merge is just not much working for me right now, so bad that I started to think it must be me. However, after spending about an hour with this and re-doing the stack multiple times, I am still getting nowhere. So I decided to create a topic. Happy to be told I am an idiot. If I just can get this image properly stacked, I need it urgently. 

Here my setup:

• Dell XPS8930
• Nvidia 2060 GPU
• Windows 10 Pro, 21H1, latest patch level 19043.1348
• Affinity Photo 1.10.4.1198 (latest version as far as I am concerned) 

What am I trying to do:

• Focus merge 14 TIFF images, RAW developed in DxO Photolab 4
• It kind of works but have multiple issues

Issues:

• Issue No 1.: There is a blurred line at the bottom of the image even tough there is enough in-focus material to produce a top to bottom sharp image. (see image 1)

To see if I can improve the qualityOriginal Files.zip, I went to Sources and toggle source preview. 

• Issue No 2.: If I click and select an image at the bottom of the stack, it always jumps somewhere into the middle of the stack and I struggle to see what I actually have selected (see image 2). 
• Issue No 3.: Even though I cannot see it anymore, it still seems to keep its selection however. So if I toggle the source preview, a white page appears when I have selected the very bottom image. It is as if this image hasn't been used. If I choose the second from the bottom, it works as expected (see image 2). 
• If I use
• Issue No 4: If I select/toggle images from the top of the stack, they show strange artefacts around the edges, something that clearly is not present in the original images (see image 3). The lower I go in the stack, the less pronounced the artefacts are. 

To make it easier to replicate the problems, I have attached my original images. 

Thanks very much for your help.

Regards

Phil 

==============================================

Image 1

Image 2

Image 3

2034909115_OriginalFiles.zip

[RichardMH]

Downloaded your images and have the same problems. Only fix I can think of is to do the focus merge then load some of the other images and with judicious masking get rid of the blurry bits. Or get one of the specialist focus stacking programs.

[DigitalStirling]

1 hour ago, RichardMH said:

Downloaded your images and have the same problems. Only fix I can think of is to do the focus merge then load some of the other images and with judicious masking get rid of the blurry bits. Or get one of the specialist focus stacking programs.

Thanks for your effort Richard, this makes me feel a bit better. I genuinely thought I am loosing the plot here. Photo wasn't too bad for me for the last two years from a stability and bug perspective. However, the merge tool seems to be completely messed up in the current version. 

The stability is not great either at the moment. When I use the Inpainting Brush to clean-up an image, I have regular application freezes. I never used to have that in that past. 

[RichardMH]

Freezes might be OpenCl problems. I get regular freezes with it on. Have you tried turning it off? (Edit->Preferences->Performance).

[DigitalStirling]

27 minutes ago, RichardMH said:

Freezes might be OpenCl problems. I get regular freezes with it on. Have you tried turning it off? (Edit->Preferences->Performance).

Mine was enabled, so will try that.

[DigitalStirling]

3 hours ago, RichardMH said:

Downloaded your images and have the same problems. Only fix I can think of is to do the focus merge then load some of the other images and with judicious masking get rid of the blurry bits. Or get one of the specialist focus stacking programs.

Just installed Helicon Focus 7 and got a 30-day test license that allows me to save files. Got it to work in 2 Minutes!

This solves my immediate problem and allows me to test Helicon properly. I was interested in trying it out anyway, so this is a good opportunity. 

[Old Bruce]

I am not going to download the files (too large) but I think this may be due to a shift in the area due to either the zooming caused by racking the lens out or moving the subject closer to the lens. Or even tripod slippage.

What I am trying to say is that you have a slightly larger image than any one individual frame and the software is stretching the edge pixels to match. Choose the first and last frames, closest focus and furthest focus. Now compare the actual areas in the frames, is there a mismatch?

[NotMyFault]

On 11/18/2021 at 6:31 PM, DigitalStirling said:

Issue No 1.: There is a blurred line at the bottom of the image even tough there is enough in-focus material to produce a top to bottom sharp image. (see image 1)

Hi,

 

i downloaded your images. Actually there is not enough in-focus material for the bottom line. The in-focus area is cut off at the bottom of the source images.

The image PB180054_TIFF is sharp at the bottom, but it doesn't contain any data required to fill the bottom part (which is present in the later images).

The later image contain more parts of the bottom area, but there it is completely out of focus.

This is quite normal due to focus shift. If you put a ruler at the side of the images you would see the effect clearly in the source images.

In the screenshot i marked the sharp in-focus area with a red frame in both the first and the last source image.

To get the bottom part in the focus stack, you need to include more of that area in the source images.

I've done lots of focus stacks with Affinity Photo and the results were always quite excellent if you feed it with the required source material. The in-focus area must be surrounded by a large enough buffer of out-of-focus area, as the focus shift lets the image breath (the size could change quite a lot, or the object can shift within the sensor plane as visible in your example)

 

[NotMyFault]

Another way to see this:

The last image covers 112% of the area of the first image (manually stacked, upper with 50% opacity

 

[DigitalStirling]

10 hours ago, NotMyFault said:

Hi,

 

i downloaded your images. Actually there is not enough in-focus material for the bottom line. The in-focus area is cut off at the bottom of the source images.

The image PB180054_TIFF is sharp at the bottom, but it doesn't contain any data required to fill the bottom part (which is present in the later images).

The later image contain more parts of the bottom area, but there it is completely out of focus.

This is quite normal due to focus shift. If you put a ruler at the side of the images you would see the effect clearly in the source images.

In the screenshot i marked the sharp in-focus area with a red frame in both the first and the last source image.

To get the bottom part in the focus stack, you need to include more of that area in the source images.

I've done lots of focus stacks with Affinity Photo and the results were always quite excellent if you feed it with the required source material. The in-focus area must be surrounded by a large enough buffer of out-of-focus area, as the focus shift lets the image breath (the size could change quite a lot, or the object can shift within the sensor plane as visible in your example)

 

Hey @NotMyFault, thank you very much for this!

This is the answer to this part of the problem. I did notice quite heavy lens breathing and your explanation hits it on the head. As the image shifts, the lower section of the image indeed lacks enough in-focus image. This shows my lack of experience with this, but one can always learn :-). 

I am currently playing with Helicon, too. Comparing what it does to Affinity, it simply crops the image with the out-of-focus section (actually a lot more I found) to be on the safe side I assume. If I manually crop the Affinity result with a tiny bit at the bottom, I end up with more estate than with Helicon, which tells me that Affinity does indeed a good job. 

This forum is great. Having a big pool of folks that know what they are doing and can offer sound advice is fantastic! 

Cheers

Phil